In the manufacture of garments from dyed cellulosic fabric, e.g., blue jeans from indigo-dyed denim, it is common to treat the denim so as to provide a “stone-washed” look (localized abrasion of the color in the denim surface). Performance of endoglucanase on denim is strongly believed to depend on the structure and chemical nature of the enzyme.
In denim biostoning, abrasion and backstain of indigo are the two key performance indicators for a given endoglucanase. It is rare for a single endoglucanase to both provide high abrasion of denim and control indigo backstain to an acceptable level. The interaction between endoglucanase-indigo, endoglucanase-cellulose, and application pH's also contribute to denim abrasion and indigo backstain.
WO 98/45395 describes detergent compositions employed in low water wash processes. WO 97/15660 describes a method for preparing a crystalline endoglucanase enzyme. WO 95/16782 describes a novel truncated endoglucanase protein from Trichoderma longibrachiatum in reduced redeposition (backstaining) of dye onto the fabric while maintaining an equivalent level of abrasion.
WO 91/17243 and WO 95/09225 (Novo Nordisk) describe a process using a single-component endoglucanase denoted EGV with a molecular weight of 43 kD derived from Humicola insolens strain DSM 1800. WO 94/21801 (Genencor) describes the use in “stone washing” of a single-component endoglucanase called EGIII derived from Trichoderma longibrachiatum. WO 95/16782 (Genencor International) suggests the use of other single-component endoglucanases derived from Trichoderma in “stone washing”.
A general problem in known “stone washing” methods is that of backstaining, i.e., a phenomenon whereby dye already removed by abrasion deposits on parts of the fabric or garment so as to even out the desired variation of color density or to discolor any light-colored parts of the garment. There is a need in the art for new endoglucanases that have good performance in denim abrasion.